September 17, 2006 It makes sense that an agency vested with the responsibility of investigating the feasibility of promising ideas such as the U.S. Defense Advanced Research Projects Agency (DARPA) occasionally says “no, that mousetrap won’t fly” and that appears to be what’s happened with the canard rotor/wing (CRW) X-50A Dragonfly unmanned air vehicle (UAV) we reported on last December.